Code 26 and ECT Sensor

[Von Hayek]

My '94 threw a Code 26 when I was trying to get the lockers to work.

Center diff doesn't lock when shifted into Low, and neither axle diff lock works.

Also, the "Pwr" light does not come on when the ECT button is pushed.

So, I was sitting in the driveway shifting it into and out of Low when the center diff locked, the ABS light came on (which is normal I believe), and the check engine light immediately came on. Code 26.

One of things that the factory service manual list as a potential culprit for a 26 is the ECT Sensor. Since the "Pwr" indicator doesn't come on, this seems like a good place to start. Thoughts? I'm assuming the sensor is on the tranmission? Anyone dealt with this scenario?

 

[Von Hayek]

Anyone dealt with this? The CEL popped at the exact same time I finally got the center diff to lock.

 

[Von Hayek]

For posterity's sake, I figured I would post the solution to this for anyone searching in the future. My problem turned out to be a bad ECT sensor.

Symptoms were an intermittent code 26, rough idle, and a louder exhaust note.

When I pulled the sensor to test it, it was cracked a bit around the base. I tested it anyway and resistance moved as it should with temperature change, but with a bit lower resistance to corresponding temperature than spec.

I installed a new sensor, and so far so good.

 

[Red Merle]

Howdy campers,

So, I have been having some intermittent rough idle symptoms and I finally threw a code 26 on the ol' OBD1 unit which points to a bad ECT sensor and the last thread I could find regarding it's replacement was five years old and well, I think it's always smart to keep these topics in the same place so that the next guy can find them and here we are.

I have a new unit coming in and my question is regarding the fitment of the 19MM socket on the sensor. Some people have reported that the deep well socket won't fit around the electrical fitting and that they had to break it off to make it work. That's not the end of the world if I can eventually get the old sensor out, but how is this not going to cause a problem when I go to install the new one? The FSM says use a socket.

Is there a trick to this, or what?

 

[Red Merle]

I have no idea what all the fuss was about in the other threads. I just installed the new sensor. Took less than 10 minutes and the CEL is gone and the truck idles fine now.

 

[cc93cruiser]

I have no idea what all the fuss was about in the other threads. I just installed the new sensor. Took less than 10 minutes and the CEL is gone and the truck idles fine now.

About to swap mine in a couple days, was just wondering how much coolant did you lose while swapping them out?